Most floor-mount toilets take 5/16 × 2-1/4-inch closet bolts, like the Danco 88773A with a snap-off top. For a tall base or 1/4-inch holes, use the extra-long Oatey Johni-Bolt 90154; if bolts keep flopping over while you set the bowl, the Oatey Johni Quick Bolt 90907 holds them upright. Pick brass so they do not rust in place.
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This guide covers the two bolts that hold a floor-mount toilet to the closet flange, plus caps and tightening.
Closet bolts compared
| Bolt | Size | Choose it when |
|---|---|---|
| Danco 88773A | 5/16 × 2-1/4 in. | A standard floor-mount toilet and you want a snap-off top instead of sawing |
| Oatey Hercules Johni-Bolt 90154 | 1/4 × 3-1/2 in. | The bowl has 1/4-inch holes or a tall base where 2-1/4-inch bolts come up short |
| Oatey Hercules Johni Quick Bolt 90907 | 5/16 × 3-1/2 in. | Bolts that keep spinning or flopping; the push-and-turn washer holds them upright |
Closet bolts (also called toilet bolts or T-bolts) slide into the slots of the closet flange, stand up through the holes in the toilet base, and take a washer and nut on top. A pair holds the bowl down on the wax ring.
Danco 88773A: 5/16 × 2-1/4 with break-away top
Choose Danco 88773A for a typical replacement on a standard floor-mount toilet. 5/16 × 2-1/4 inches is a common replacement size, and the break-away feature named in the product title lets you snap off the extra length after tightening instead of cutting it.
On October 15, 2026, the standard new offer sold by Amazon.com showed limited stock with model 88773A, two pieces, and a 5/16 × 2-1/4-inch size.
Skip it if your toilet base is thick enough that 2-1/4 inches will not reach a full nut, or if the bowl holes only fit 1/4-inch bolts.
Check Danco 88773A closet bolts on Amazon →
Oatey Hercules Johni-Bolt 90154: extra-long 1/4-inch
Choose the Johni-Bolt 90154 when you need extra length or a 1/4-inch diameter. Oatey’s Johni-Bolt page (oatey.com) describes a patented brass closet bolt with a snap-off slot and a captive washer that keeps the bolt upright and stops it falling through the flange. It is packaged in pairs with two washers and two brass acorn nuts.
The Amazon listing shows 1/4 × 3-1/2 inches, model and part 90154. On October 15, 2026, the standard new offer from a third-party seller showed stock.
Skip it if the toilet base holes are sized for 5/16-inch bolts and you prefer a snug fit; choose a 5/16 bolt instead.
Check Oatey Johni-Bolt 90154 extra long on Amazon →
Oatey Hercules Johni Quick Bolt 90907: stops wobbly bolts
Choose the Johni Quick Bolt 90907 when bolts keep tipping over while you set the toilet, or when you are tired of double-nutting them. Oatey’s Quick Bolt page (oatey.com) says you push down on the gold plastic washer and turn to tighten, and that the kit has two plastic washers, two solid brass bolts, and two cap nuts with stainless washers. Part 90907 is one of the four variations Oatey lists for this product.
The Amazon listing shows 5/16 × 3-1/2 inches. On October 15, 2026, the standard new offer from a third-party seller showed stock.
Check Oatey Johni Quick Bolt 90907 on Amazon →
1/4 or 5/16 inch, and how long
Check the slot in the flange and the holes in the toilet base before buying. 5/16-inch is the most common closet-bolt size for floor-mount toilets, but some bowls have holes that only fit 1/4-inch.
Length depends on the base. The bolt has to come up through the base far enough for the washer and a full nut, plus room for the cap. Standard bolts are about 2-1/4 inches; tall or thick bases, or a flange spacer under the toilet, call for 3 to 3-1/2-inch bolts.
Brass and stainless resist rust in a damp bathroom. Plain zinc-plated steel can rust and seize, which makes the next toilet pull harder.
Measure before you buy
With the toilet off, measure three things. First, the width of the flange slot: a 5/16-inch bolt head needs a slot it can slide into and lock under, and a cracked or worn slot will let any bolt spin. Second, the diameter of the holes in the toilet base; slip a drill bit or the old bolt through to compare. Third, the height of the base at the bolt holes, from the floor to the top of the porcelain.
The bolt has to reach from the flange slot, up through the base, with enough thread above the porcelain for the washer and a full nut. If a 2-1/4-inch bolt would be close, buy the longer bolt; trimming extra length is easy, but a short bolt cannot be fixed.
Also look at the flange itself. Plastic flanges with a metal ring hold bolts better than plain plastic slots, which can strip. If the flange sits below the finished floor, solve that first with our low flange guide.
Bolt caps
The caps snap over the nut and bolt end for a clean look. Many caps have a plastic base washer that goes on first; the cap clips onto it. Buy caps that match your bolt length, or trim the bolt so the cap sits flat on the toilet.
Some toilet makers sell matching caps in the bowl’s color. A cap that will not seat is almost always a bolt that was left too long.
The closet bolt wrench and installing without cracking the bowl
A small wrench or a 7/16 or 1/2-inch socket on a short ratchet handles most closet-bolt nuts; a deep socket reaches nuts on long bolts. Our deep socket set guide covers sizes.
Tighten the nuts a little at a time, alternating sides, until the bowl is firm. Vitreous china cracks if you crank one side hard. If the toilet still rocks on a level flange, shim it rather than overtightening; see our toilet shim guide.
Trim excess length with a hacksaw or snap off a break-away top, then fit the caps. If a bolt spins in a broken flange slot, the flange needs repair first; our wobbly toilet guide covers that.
When you replace the bolts
Always use new bolts when you pull a toilet for a new wax ring; old ones are often corroded and the nuts may not come off cleanly. Our wax ring replacement guide walks through the full job.
Some wax ring kits include bolts. Check their material and length, and buy separate brass bolts if your base is tall or the kit bolts are plain steel.
Frequently asked questions
What size are toilet closet bolts?
Most are 5/16 inch by 2-1/4 inches. Some older or smaller bowls take 1/4-inch bolts, and tall bases need 3 to 3-1/2-inch lengths.
Should closet bolts be brass?
Brass or stainless resists rust in a damp bathroom. Plain steel can rust and seize, which makes the next toilet removal harder.
How do I keep closet bolts from falling over?
Use bolts with a captive washer, like Oatey Johni-Bolts, or a push-and-turn system like the Johni Quick Bolt, which holds the bolt upright in the flange.
How tight should closet bolt nuts be?
Snug and even. Alternate sides a little at a time until the bowl is firm. Overtightening can crack the china.
What if the bolt is too long for the cap?
Cut it with a hacksaw or snap off a break-away top after tightening, then fit the cap.
How we chose
This document-based guide makes no hands-on testing claim. We read Oatey’s current Johni-Bolt, Johni Quick Bolt and toilet-bolt pages; Danco’s site could not be reached, so its details come from the Amazon listing. On October 15, 2026, all three linked standard new offers showed stock and matched their model or part numbers. Read our selection method and about Plumbing Picks.
Primary sources
- Oatey Hercules Johni-Bolt and Johni-Bolt XL (oatey.com): snap-off slot, captive washer, pair packaging, variations.
- Oatey Hercules Johni Quick Bolts (oatey.com): push-and-turn washer, kit contents, variation 90907.
- Oatey toilet bolts category (oatey.com): solid brass Johni-Bolts with snap-off slot and captive washer.